Maskell. — On Coccididae. 135 



Mytilaspis citricola, Packard. 



Aspidiotus citricola, Packard ("Guide to the Study of 

 Insects," 1870, p. 527). 



Mytilaspis citricola, Packard (Comstock, "U.S. Ag. 

 Eep.," 1880). 

 This insect occurs on the rind of some oranges forwarded 

 to nie by Mr. Eaithby, of Inangahua. The oranges, as I 

 understand, came originally from Fiji, and the species must 

 therefore be added to the Fijian fauna. My specimens have 

 perhaps a slightly broader and thinner female puparium, and 

 a rather lighter colour than the type. But, after comparing 

 them with undoubted specimens of M. citricola, forwarded to 

 me by Dr. F. Low, of Vienna, I have no doubt of their iden- 

 tity. They seem, indeed, to be a good example of the neces- 

 sity, as I think it, of neglecting in the Diaspid group mere 

 outward appearance, and relying chiefly on microscopic dif- 

 ferentiation. If only the colour and form of the puparia were 

 taken into account it would be easy to make half-a-dozen 

 species of the specimens on a single piece of orange-peel. 



Genus Diaspis, Costa. 



Diaspis santali, mihi, " Scale-Ins. of N.Z.," p. 47. 



This insect has in the last three or four years replaced 

 and almost driven out Aspidiotus camellicB on Euonymus and 

 Acacia trees about Wellington. The two may still be found 

 together sometimes, A. camellicB being much the less fre- 

 quent : usually D. santali has taken comj)lete jDossession, the 

 trees only suflFering the more for the change. It is also ap- 

 pearing on a good many native trees in various places — cq., 

 Carpodetus, Vitcx, Mclicytus, &c. 



Genus Chionaspis, Signoret. 



Chionaspis dysoxyli, mihi, " Scale-Ins. of N.Z." p. 55. 



In the last twelve months two curious facts have occurred 

 in connection with this insect, one of which is, as far as I 

 know, unique. First, although up to 1889 I had not detected 

 the species on any other plant than Dysoxylon spcctahile, in 

 February of that year I found it occurring somewhat plenti- 

 fully on Melicytiis ramifloriis, in the Wellington public gardens. 

 In March the numbers on Mclicytus seemed to have consider- 

 ably increased ; and all through the winter these trees became 

 covered with masses of Chionaspis, not only on the leaves but 

 also on the twigs and branches, until suddenly, in August, the 

 insects disappeared as rapidly as they had come. They left 

 the plants considerably dilapidated by their attacks, although 

 these had lasted only so short a time, and that chiefly in 

 winter : at the same time, it happened that the winter of this 



